The following information was contained in a post-em by Curt Hofemann, curt_hofemann@yahoo.com:

Beatrice de Valle (or Vaux), wife of William Briwerre, was almost certainly the daughter of Hubert de Vaux, baron of Gilsland (see ID 20718?), Cumberland, by his wife, Grace.

The evidence for this is slim but compelling. Beatrice had property in Devonshire as her maritagium. The early history of this property is shrouded.

However, Hubert de Vaux is known to have owned property in Devonshire, and probably lived there during part of his life. Beatrice de Valle had a daughter Grace Briwerre who I presume was named for her mother, Grace de Vaux. Grace was rather rare as a woman's name in that period. I have proven that William Briwerre acquired property from one of Beatrice's Vaux brothers and I have proven that William Briwerre was involved in a suit with the widow of another brother. If nothing else, this proves that the two families knew each other well.

I should also note that Beatrice de Valle was almost certainly the mother of Henry Fitz Count, bastard son of Reginald, Earl of Cornwall. This is indicated by two successive charters which unfortunately I don't have in hand. In these two charters, Henry Fitz Count makes a gift to some religious house and in the next charter, Beatrice's Briwerre son refers back to his "brother" without naming him, as if the parties understood who he meant. This would only make sense if the two charters were recorded at the same time and if Henry Fitz Count was the "brother" named by Beatrice's Briwerre son. The charters are published in Monasticon Exoniensis.

The name Vaux, by the way, was usually written in Latin as Vallibus but I have seen it on rare occasions as Valle. Beatrice's maiden name is given as Valle in one charter I have seen. [Ref: Douglas Richardson 25 Jan 1999 message to soc.genealogy.medieval]

Research note: numerous listings on Rootsweb Worldconnect show the above Reginald (de Dunstanville), Earl of Cornwall (bastard son of Henry I by Sybil Corbet) as Beatrice de Valle/Vaux's father & Beatrice Mortaigne/Mortain or Beatrice fitzRichard as her mother, but sources are lacking... Curt